Carbonylative Cyclization of Unsaturated Carboxylic Acids by Palladium Complexes with Phosphines() Theoretical Studies on Palladium(0, ) Complexes of Unsaturated Carboxylic Acids

摘要

The structure and reactivity of ￥e-and metallacycle form in the bis(trimethylphosphine) palladium(0) complexes with acrylic acid, methacrylic acid, crotonic acid(A group) and 3-butenoic acid, 4-pentenoic acid(B group) have been investigated by Molecular Mechanics and Extended Huckel Molecular Orbital method. The calculation shows that A groups with large value of frontier electron density of HOMO and LUMO produce ￥e-complexes instead of metallacycle. But B groups with small value of frontier electron density of LUMO, especially 3-butenoic acid, form stable metallacycle. Moreover the methyl-substituted five-membered compared with the six-membered metallacycle is energetically stable conformation.